​Justin Bartha Engaged To Be Married To Lia Smith​​

By: | 05/19/2013 07:35 PM ET

Justin Bartha is engaged to be married to his fitness trainer girlfriend, Lia Smith.

The 34-year-old actor, best known for his role as Doug Billings in The Hangover films, proposed to Smith they were on vacation at the Post Ranch Inn in Big Sur, Calif. an insider revealed to Us Weekly.

“They’re the cutest couple. She was completely surprised by the whole thing,” the source said.

“The trip to Big Sur, the engagement, the ring, everything. So cute.”

The ring is “just unbelievable, they are an amazing couple and so gorgeous together,” the insider continued.

Bartha and Smith met at the Equinox gym in Los Angeles, where she is employed. They went public about their relationship after pictures surfaced of them on a beach in Maui on New Year’s Day 2013.

The “Hangover Part III” will hit theaters Friday, May 24.